Ok so I have a freshly rebuilt z6 in my 96 civic, running an obd1 ecu dizzy and pretty much everything. well its throwing code 43 for fuel delivery system and I am having a hell of a time figuring this out. Im running the exact same setup as I was before the engine blew only things I have changed have been the motor obviously and the injectors, It ran great before the motor blew.
so far what I have replaced include

Walboro 255 fuel pump about a year ago
Aem fpr
on my second set of stock honda fuel injectors
changed out the engine temp sensor with one I had laying around
just put a new bosch o2 sensor in it


basicaly I drive it and it runs great proper fuel pressure and everything, then the cel comes on I watch the wideband lean out and it runs like complete Sheit. my idle does seem a little funky possible iacv?? any thoughts on this im kinda lost.

 

possible fuel filter, also check for gas cap

 

What would the gas cap have to do with anything?

 

on an obd2 car sometimes a loose gas cap would throw a code. don't think it will on an obd1 though.

have you ever tried cleaning or replacing the injectors you changed out?

 

Lower the pressure on the fuel tank

 

I was told the injectors were perfect, I just dont think I would have 2 sets of bad injectors I suspected the first set because they were from a junkyard car. I dont think the gas cap is the problem, the tank holds pressure I can hear it when removing the cap, and the fuel filter was spotless the last time I checked it.

 

Its such a generic code, 43 can be set by bad FPR, bad injector, bad ECT sensor, bad MAP sensor, bad 02 sensor, bad fuel, incorrect fuel pressure, bad ECU, and incorrect mechanical timing.

I fought this code on a 91 DA B18A.
most common is the 02 sensor. I did everything i could think of as far as following the ACURA service manual, and couldn't figure it out. The car went to another shop for a second opinion
and they checked the mechanical timing and it was off. Ran good ever since.

I would recommend checking the resistance between your 02 sensor and the ecu plug to see if you have continuity.



ARE you BOOSTED, if so and your not tuned that will cause problems too.

 

Figured this wouldn't hurt.

According to the Honda Shop Manual for '92-'95 Civics.

Code 43
FUEL SUPPLY SYSTEM (except D15Z1 enine)
pages 11-52

PGM-FI Control System
Troubleshooting Flowchart - Fuel Supply System

11-52
http://imgur.com/DVPGc.jpg

11-53
http://imgur.com/l91DI.jpg

Idle Control System
Troubleshooting Flowchart - Air Conditioning Signal

11-88
http://imgur.com/meGFp.jpg

11-89
http://imgur.com/Kguj2.jpg

 

I tested the injectors to see if they were leaking by blocking off the return line, it held pressure just fine so I know the injectors are good, the o2 is good, the fpr is good, the fuel pump is good, basically everything in the fuel system is good, It does idle a little funky, on cold startup it idles at 1500 rpm consistently but on warm startup it initially goes to 2k then drops down below 1k then picks back up to 2k then very very very slowly drops down to around 1500 where it pretty much stays, might go a little lower at times this leads me to believe there is a bad sensor but which one? map? Iacv? any thoughts?? Thanks for the help

 

idle surge is usually the FITV fast idle thermo valve need tightening, check the FAQ forum. could be a bad IACV, vacuum leak.

The 43 shouldn't be related. Like i said check the resistance between the O2 sensor connector and the ECU connector. That brand new 02 sensor wont do any good without an electrical connection. I would also advise checking the timing marks and making sure it is in time. Also this motor is freshly rebuilt? Are you valve clearances adjusted to spec?


If you are boosted and not tuned this could cause a 43 as well, also will cause detonation.

 

I'm checking for vacuum leaks right now, I will also check for resistance, the valves are adjusted to spec just did it about a week ago, and I am not currently turbo'd.

 

Check your wiring

 

It seems I found the problem in my EG, its a bad calibrated TPS... It was delivering more gas than needed, thats why also cannot pass the smog test.